Well-dispersed 1−6 nm diameter gold nanoparticles were intercalated into the interlayer galleries of lamellar oxides by first intercalating with poly(allylamine) (PAA) or poly(diallyldimethylammonium) ions to invert the layer charge. This reaction was demonstrated for an exfoliated fluoromica as well as a Dion−Jacobson phase layer perovskite (HCa₂Nb₃O₁₀). In the PAA case, the nanoparticles were intercalated with very little aggregation. Larger (3−6 nm diameter) gold nanoparticles could also be intercalated, but some aggregates were observed on outer surface of the host solids. FTIR spectra of the samples suggest that the weak covalent-bonding interaction between excess free primary amine groups of the PAA chains and the Au nanoparticle surface drives the nanoparticle intercalation reaction.